97Cobra_kid

hey, i think theres something wrong with my alternator. everytime i take my car out, it happens to stall every so often, only when im braking, or when it's in neutral. i noticed that everytime i rev it, or throw it into first, my battery gauge goes more towards the middle, and when i'm sitting at a light it goes down to the left and my speedometer dims. i went and got my battery checked and the guy said it's still a good battery, even though it's the stock battery,.... yeah it's 10 years old. did anyone ever have this problem?

czwalga00gt

Find the sticky about the IAC.

It's a simple fix, costs under $100.

97Cobra_kid

find the sticky? of the IAC?

timeformiller44

go get your alternator tested, they do that crap at like auto zone or something of that sort

czwalga00gt

Looks in the links at the top of the 4.6 section. It's in there somewhere.

It's the idle air controller. Or just search for IAC, its what needs replaced.

97Cobra_kid

i did get it tested, and i couldnt understand what he was saying, but my alternator came up 189 and he said thats's a little high cause it's suppose to be around 90

metaldrummer

Your idle are control valve gets stuck shut because its dirty. dont try and clean it with carb cleaner or brake cleaner -you will just eff it up big time. Buy a new one (like 80 bucks) and install it. all you need is a screw driver and 5 minutes.

97Cobra_kid

i dont know man, i just got my engine rebuilt so im not sure it would be that

czwalga00gt

It is. I'd say atleast 95% sure of it.

The IAC lets in air while the throttle is shut, enough air to keep it idling. Notice it never does it when you're on the trottle at all. It's definalty the IAC. Also, its on the throttle body assembly, just becuase the engine was rebuilt doesnt mean it was replaced. Your car has to have one, unless its equipped with ETC, and I dont know of any sub-05 mustang with ETC. Theres no need to ever replace it or put an aftermarket one on, unless it goes bad.

I'd throw a $1000 right now its the IAC.